When the notion of bringing in John Doar to enforce law and order in the coalfields was discussed and rejected at the White House Tuesday morning, the president's men were conceding that Jimmy Carter and the nation's coal miners are on a collision course.

Fear of violence by the striking United Mine Workers against coal production and coal shipments permeated White House discussion of President Carter's worst crisis. So it was suggested that the stern-faced, stern-voiced Doar, last seen as counsel at the Nixon impeachment proceedings, be brought in as a commanding figure. The idea was rejected on grounds it might betray an expectation of disorder.

Nevertheless, the discussion reflects how far the Carter men have gone in two weeks. No longer grumbling over the obstinacy of coal operators, the White House now sees itself inevitably colliding with the miners' undisciplined expectations. Neither politics nor ideology apply. What is demanded at the White House is the survival of the rule of law.

In fact, the crisis faced by Carter stems from the refusal of the miners to obey an imminent Taft-Hartley injunction to return to work. There are indeed second thoughts within the administration over the wisdom of government officials (including Secretary of Labor Ray Marshall) publicly predicting just such civil disobedience in originally advising the president against the use of Taft-Hartley.

Although the White House is pushing still further capitulations by the coal operators to UMW demands, the decision to ask for the higher 1978 wage rates under a Taft-Hartley back -to-work order came only after hot debate within the administration. Some key officials believe it is the equivalent of demanding unconditional surrender by the operators.

Nevertheless, the miners probably would not work under a Taft-Hartley edict even with the higher wage rates. If they do not, Secretary of Energy James Schlesinger has informed the president, the nation faces an additional 3 to 4 million unemployed this spring directly resulting from the strike, with incalculable millions more laid off indirectly.

The only possible solution by the administration is to encourage piecemeal contract settlements by individual coal companies to gradually increase coal production (now about one-third of normal) and thereby avert economic catastrophe. Therein is posed the central problem of law and order: to prevent operating mines from being shut down and railroads moving coal from the West from being blocked. Saboteurs also can knock out a power plant for months by wrecking a transmission line.

White House strategy is against proclaiming a federal law-enforcement program that would discourage governors from doing anything themselves. The early response has been good, particularly from a pair of Republicans. Gov. James Rhodes of Ohio publicly praised the president for coming down on the side of law and order; Gov. John Dalton of Virginia called the White House to say he has ordered a well-publicized review off all state penalties for interfering with truck passage.

Ultimately, however, the responsibility is the president's. He has informed key aides that he is determined to move all coal being mined without interference from anybody.

This collision course reflects a transformed White House attitude about the striking miners. Presidential aides reject romanticized concepts of individualistic mountain men, and now regard the strikers as typically self-indulgent in a society of ever-rising expectations.

Similar disillusionment has set in about labor leaders. The president's men have no faith in the UMW's national or district officials. Criticism of Carter's coal-strike performance by AFL-CIO President George Meany in Florida brought outrage. "We're getting up at 4 every morning to try to handle this," one official complained, "while Meany and his people are sniping at us from the beach in Miami."

The coal crisis may become a watershed in the Carter administration. It has transformed the relationship with labor; it has forced the White House to acknowledge the lack of experienced operatives to handle crises; and most important, it has brought home the weakened state of the post-Watergate presidency.

Carter's well-delivered pep talk in the White House to coal operators and UMW leaders had no effect. Nor were then-deadlocked negotiators moved by the president's remarks, piped into the White House from his Providence, R.I., press conference (UMW President Arnold Miller snoozed through it.)

After all the talk about the imperial presidency, the weakened state of the office now becomes clear. In this and other ways, the coal crisis - if it can be endured without economic catastrophe - could be the beginning of wisdom for the Carter White House.